FAUNAL SUCCESSION IN THE LOWER CARBONIFEROUS LIMESTONE. 189 
THE SUBZONES 
Of the Dibunophyllum Zone (D). 
D,:— 
8 | D, ( Cyathawonia’ Beds) :— 
Lonsdalia duplicata enters and attains a Cyathaxonia rushiana. 
maximum. | ‘ Cyathazxonia’ contorta. 
Cyclophyllwm attains a maximum. | Zaphrentis oystermouth- 
Koninckophylla of the typical group attain | ensis. 
& maximum, and include compound forms. | Michelinia favositoides. 
Diphyphyllum gracile enters. 
Lonsdalia floriformis enters and attains a maximum, 
Cyathophyllum regium (a compound Clisiophylloid species) enters and attains 
a maximum. 
Diphyphyllum lateseptatum enters. 
i 
Dibunophylla and Koninckophylla of simple structure enter and attain 
maxima, 
Carcinophyllum @ attains a maximum at extinction. 
Cyathophyllum murchisoni (a Clisiophylloid species) attains a maximum. 
[Productus giganteus enters—1st maximum. | 
VISEAN. 
Of the Seminula Zone (S$). 
8, [a mutation of Productus ‘ Cora’ indexes the subzone]:— 
Carcinophyllum @ enters and becomes common. 
[The entrance of Cyrtina carbonaria marks the base in the 8.W. Province], 
§,:— ‘ 
Carcinophyllum mendipense enters. 4 
Caninia bristolensis (a Cyathophylloid species) attains a maximum. 
Clistophyllum ingletonense attains a maximum. 
Of the Syringothyris Zone (C). 
¢, -— 
‘Cyathophyllum (a Caninoid species) enters and attains a maximum. 
C, :— 
a . . 
Caninia u.sp. is characteristic of the base (7). 
Caninia cornucopie attains a maximum. 
Cyathophyllum patula (a Zaphrentoid species) enters and attains a maximum. 
Of the Zaphrentis Zone (Z). 
Z, :— 
Zaphrentis koninckt enters and attains a maximum. 
Zaphrentis omaliusi abundant, 
Eaninia cornucopie enters. 
a 
Zaphrentis delanoui attains a maximum. 
[Maximum of Spirifer clathratus and 8S. tornacensis.] 
TOURNAISIAN 
Of the Cleistopora Zone (K). 
K, (maximum of Spiriferina cf. octoplicata) :— 
Cleistopora attains a maximum. 
[Productus bassus enters and attains a maximum.] 
N.B.—The information enclosed in square brackets regards the Brachiopod sequence ; 
only those facts which are diagnostic of zones or subzones are introduced. 
Note on Dy and D; :— 
D constitutes the continuation and apotheosis of the earlier D, fauna; it is t 
expressed in the fauna of the ‘Main Limestone’ of the ‘ Yoredales.’ 
D; connotes a phasal fauna later than the beginning of D,, and contemporaneous, in part, 
with Dy. An extension of this fauna is, locally, intercalated in the ‘becheri Beds’ of 
Lower Pendleside (P). : sf it 
ypically 
